I am building a water jet cutter using Arduino Uno and CNC shield for control. The CNC shield uses A4988 drivers to control the stepper motors. I uploaded the GRBL (for this shield) firmware to the Arduino and got ready to use Universal G-code Sender to send g-code instructions that the machine will work on. Now my question is this: if I want to choose to work on full step, half step or 1/16th step mode, does the Arduino, shield or the GRBL firmware know what my option is? I am asking this in order to know if I can use another motor driver (if I choose full step and the GRBL handle it well then I can use L297 driver for example, which only work on full and half step mode). I hope I made it clear...

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    \$\begingroup\$ Rather than use bold you should hyperlink to the datasheets or project home pages. Most people aren't going to know what GRBL is, for example. \$\endgroup\$ – Transistor Jan 12 '19 at 19:01

Any stepper controller won't know or care if the driver is using full step or some fractional micro-step. All it needs to know is the number of steps per unit distance. For Grbl this is configured in the $ parameters.

Table 1. Default stepper configuration for GRBL 1.1.

$100=250.000    X steps/mm
$101=250.000    Y steps/mm
$102=250.000    Z steps/mm

Reference: Grbl 1.1 Configuration.

Grbl is a free, open source, high performance software for controlling the motion of machines that move, that make things, or that make things move, and will run on a straight Arduino. If the maker movement was an industry, Grbl would be the industry standard. Source: Grbl home.

  • \$\begingroup\$ I know but when UGS generates the G-code for 1/16th step mode while I am actually using full step mode, it will give me the wrong number of steps, right?? \$\endgroup\$ – Yuri Jan 12 '19 at 19:15
  • \$\begingroup\$ I'm not familiar with UGS and can't find the configuration settings on the website but I presume it's just a matter of configuring UGS and Grbl the same way. Can you point me to the UGS configuration page? \$\endgroup\$ – Transistor Jan 12 '19 at 19:39
  • \$\begingroup\$ github.com/gnea/grbl/wiki/Grbl-v1.1-Configuration \$\endgroup\$ – Yuri Jan 12 '19 at 20:31
  • \$\begingroup\$ youtube.com/watch?v=-ssuoF2oXGg \$\endgroup\$ – Yuri Jan 12 '19 at 20:32
  • \$\begingroup\$ Yuri, I already had a link to the Grbl configuration manual in my answer. You've linked to an 18 minute YouTube video. Why? \$\endgroup\$ – Transistor Jan 12 '19 at 20:58

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